The present invention relates to an apparatus for detecting counterfeit paper currency.
Ever since the paper currency was invented and put into use, the governments throughout the world have been concerned with the problem of counterfeiting. As the duplicating and printing, and especially the photocopying technologies have advanced over the years, it is more difficult than ever to distinguish between a counterfeit and a legitimate paper currency. The problem of counterfeiting paper currency is and has been a major concern of many governments around the world.
In response to the ever-growing concern of counterfeiting, devices have been developed for detecting counterfeit currency. For example, U.S. Pat. No. 5,063,163 discloses a method of detecting counterfeit paper currency where a test solution having an initial color is applied to an area of a paper currency to be tested. After waiting for a predetermined time period, the color of the test area is compared with a predetermined standard to determine if a reaction has taken place. If the tested currency is a counterfeit paper currency, the test solution changes its color from the initial color to a black coloration. Even though the above solution is relatively simple, it is not always reliable.
Recently, another counterfeit detecting solution has been introduced, as described in U.S. Pat. No. 6,714,288. Paper currency now includes a polymer thread, which is embedded vertically in the paper to the right of the portrait and indicates the currency's denomination. This thread glows orange when held under an ultraviolet light. The '288 patent discloses an apparatus incorporating an ultraviolet lamp for currency examination. Unfortunately, such conventional devices utilizing ultraviolet lamps are expensive to manufacture, and in most cases, are rather bulky and complex in design.
Therefore, there is a need in the art for a simple apparatus for detecting counterfeit currency.